Sonny Gilzean is Butch Gilzean's nephew and ran the Magic Mushroom Ring while Butch was temporarily in control of Gotham's underworld.
Catching Selina Kyle and Bruce Wayne
At some point, Sonny got involved with his uncle's crime organization. In order to grow the magic mushrooms, Sonny enlisted the assistance of Ivy Pepper. Sonny later caught Bruce Wayne and Selina Kyle trying to rob him. When Sonny attempted to beat up Selina, Bruce called him out for it, causing him to beat up Bruce. Selina managed to break free of the thug restraining her, catching Sonny off guard, and allowing Bruce to punch him out cold, they then proceeded to run off with his money and a small supply of the mushrooms.
- This was the second time Bruce was able to beat a person into submission, the first being Tommy Elliot.